System, Device, and Method for Generating Stimulation Waveform Having a Paresthesia-Inducing Low-Frequency Component and a Spread-Spectrum High-Frequency Component

ABSTRACT

A pulse generator includes charging circuitry configured to provide electrical power to the pulse generator. The pulse generator includes communication circuitry configured to conduct wireless telecommunications with external programming devices. The telecommunications contain programming instructions sent from the external programming devices. The pulse generator includes stimulation circuitry configured to generate electrical pulses based on the programming instructions. The electrical pulses include a first component that is paresthesia-inducing and a second component that is non-paresthesia-inducing.

CROSS REFERENCE TO RELATED APPLICATION

This application claims benefit of U.S. Provisional Application No.62/505,209, filed May 12, 2017, which is incorporated herein byreference in its entirety.

BACKGROUND

The invention relates to a stimulation system, such as spinal cordstimulation system, a peripheral nerve stimulation system, or a pelvicnerve or sacral nerve stimulation system. The stimulation system uses apulse generator to provide electrical stimulation for a patient, forexample to the spinal cord, a peripheral nerve, or a sacral nerve or apudendal nerve, in order to treat problems such as chronic pain orincontinence. The pulse generator is coupled to a stimulation leadhaving one or more electrodes at a distal location thereof. The pulsegenerator provides the electrical stimulation through the electrodes viaa body portion and connector of the lead. Stimulation programming ingeneral refers to the configuring of stimulation electrodes andstimulation parameters to treat the patient using one or more implantedleads and its attached pulse generator. For example, the programming istypically achieved by selecting individual electrodes and adjusting thestimulation parameters, such as the shape of the stimulation waveform,amplitude of current in mA (or amplitude of voltage in V), pulse widthin microseconds, frequency in Hz, and anodic or cathodic stimulation.

Despite recent advances in medical technology, existing stimulationmethods, systems, and devices still have various shortcomings. Forexample, one problem faced by existing stimulation systems and methodsis that they cannot provide a stimulation waveform that can optimize thestimulation therapy.

Therefore, although existing systems and methods for performingneurostimulation are generally adequate for their intended purposes,they have not been entirely satisfactory in all respects.

SUMMARY

One aspect of the present disclosure involves a pulse generator. Thepulse generator includes charging circuitry configured to provideelectrical power to the pulse generator. The pulse generator includescommunication circuitry configured to conduct wirelesstelecommunications with external programming devices, thetelecommunications containing programming instructions sent from theexternal programming devices. The pulse generator includes stimulationcircuitry configured to generate electrical pulses based on theprogramming instructions. The electrical pulses include a firstcomponent that is paresthesia-inducing and a second component that isnon-paresthesia-inducing. In some embodiments, the first component has afixed frequency, and the second component has a spread-spectrumfrequency range that is greater than the fixed frequency.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isemphasized that, in accordance with the standard practice in theindustry, various features are not drawn to scale. In fact, thedimensions of the various features may be arbitrarily increased orreduced for clarity of discussion. In the figures, elements having thesame designation have the same or similar functions.

FIG. 1 is stylized overview of the human nervous system.

FIG. 2A is a diagram illustrating an example sacral implantation of aneurostimulation lead according to various embodiments of the presentdisclosure.

FIG. 2B is a simplified diagram illustrating an implantableneurostimulation system for stimulating nerves according to variousembodiments of the present disclosure.

FIG. 2C is a simplified diagram illustrating a side view of a humanspine according to various embodiments of the present disclosure.

FIG. 2D is a simplified diagram illustrating a frontal view of a humanspine for a context of spinal cord stimulation according to variousembodiments of the present disclosure.

FIGS. 3A-3B illustrate an example pocket programmer controller inaccordance with one embodiment of the present disclosure.

FIG. 4 is a block diagram of components of the example pocket controllerof FIGS. 3A-3B in accordance with one embodiment of the presentdisclosure.

FIGS. 5A-5B illustrate an example patient programmer charger controllerin accordance with one embodiment of the present disclosure.

FIG. 6 is a block diagram of components of the example patientprogrammer charger of FIGS. 5A-5B in accordance with one embodiment ofthe present disclosure.

FIG. 7 is a block diagram of a clinician programmer according to oneembodiment of the present disclosure.

FIG. 8 is a block diagram of an implantable pulse generator according toone embodiment of the present disclosure.

FIG. 9 is a diagrammatic block diagram of a patient feedback deviceaccording to an embodiment of the present disclosure.

FIGS. 10A and 10B are exterior views of the patient feedback deviceaccording to embodiments of the present disclosure.

FIG. 11A is a side view of a patient-feedback device inserted in themouth of a patient according to an embodiment of the present disclosure.

FIG. 11B is a side view of a patient-feedback device with opticalsensing according to an embodiment of the present disclosure.

FIG. 11C is a side view of a patient-feedback device activated by a footof a patient according to an embodiment of the present disclosure.

FIG. 12 is a simplified block diagram of a medical system/infrastructureaccording to various aspects of the present disclosure.

FIG. 13 is an illustration of a portion of a stimulation waveformgenerated by a pulse generator in a time domain according to variousaspects of the present disclosure.

FIG. 14 is an illustration of the stimulation waveform of FIG. 13 in afrequency domain according to various aspects of the present disclosure.

FIGS. 15-16 illustrate histograms associated with a stimulation waveformaccording to various aspects of the present disclosure.

FIG. 17 illustrates an example stimulation waveform in a time domainaccording to various aspects of the present disclosure.

FIG. 18 illustrates a simplified example stimulation waveform without aspread-spectrum stimulation component in a time domain according tovarious aspects of the present disclosure.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments, or examples, for implementing different featuresof the invention. Specific examples of components and arrangements aredescribed below to simplify the present disclosure. These are, ofcourse, merely examples and are not intended to be limiting. Variousfeatures may be arbitrarily drawn in different scales for simplicity andclarity.

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways.

The human nervous system includes a complex network of neurologicalstructures that extend throughout the body. As shown in FIG. 1, thebrain interconnects with the spinal cord which branches into thebrachial plexus near the shoulders and the lumbar plexus and sacralplexus in the lower back. The limb peripheral nerves of the arms extenddistally from the brachial plexus down each arm. Similarly, the limbperipheral nerves of the legs extend distally from the lumbar plexus andsacral plexus. A number of the larger limb peripheral nerves areidentified in FIG. 1. As discussed further below, certain aspects of thepresent invention are particularly well suited to stimulation of thepudendal nerves and the sacral nerves, including those identified inFIG. 1.

FIG. 2A is a simplified diagram illustrating implantation of aneurostimulation lead 10. In the example of FIG. 2A, lead 10 is insertedinto the body of a patient 12, and implanted posterior to one of dorsalforamen 14 of sacrum 16. However, lead 10 alternatively may bepositioned to stimulate pudendal nerves, perineal nerves, sacral spinalnerves, or other areas of the nervous system. Lead 10 may be implantedvia a needle and stylet for minimal invasiveness. Positioning of lead 10may be aided by imaging techniques, such as fluoroscopy. In someembodiments, a plurality of stimulation leads may be provided.

FIG. 2B is a diagram illustrating an implantable neurostimulation system19 for stimulating a nerve, such as a sacral nerve, via the lead 10.Neurostimulation system 19 delivers neurostimulation to the sacralnerves or other regions of the nervous system known to treat problemsincluding, but are not limited to: pelvic floor disorders, urinarycontrol disorders, fecal control disorders, interstitial cystitis,sexual dysfunction, and pelvic pain. As shown in FIG. 2B, system 19includes lead 10 and an implantable pulse generator (IPG). In addition,a proximal end of stimulation lead 10 may be coupled to a connectorblock 21 associated with the neurostimulator 20.

In some embodiments, the neurostimulator 20 includes an implantablepulse generator (IPG), and delivers neurostimulation therapy to patient12 in the form of electrical pulses generated by the IPG. In the exampleof FIG. 2B, the neurostimulator 20 is implanted in the upper leftbuttock of patient 12, but it is understood that the neurostimulator 20be implanted at other locations in alternative embodiments.

The lead 10 carries one or more of stimulation electrodes, e.g., 1 to 8electrodes, to permit delivery of electrical stimulation to the targetnerve, such as the sacral nerve. For example, the implantableneurostimulation system 19 may stimulate organs involved in urinary,fecal or sexual function via C-fibers or sacral nerves at the second,third, and fourth sacral nerve positions, commonly referred to as S2,S3, and S4, respectively. In some embodiments, the neurostimulator 20may be coupled to two or more leads deployed at different positions,e.g., relative to the spinal cord or sacral nerves.

The implantable neurostimulation system 19 also may include a clinicianprogrammer 22 and a patient programmer 23. The clinician programmer 22may be a handheld computing device that permits a clinician to programneurostimulation therapy for patient 12, e.g., using input keys and adisplay. For example, using clinician programmer 22, the clinician mayspecify neurostimulation parameters for use in delivery ofneurostimulation therapy. The clinician programmer 22 supports radiofrequency telemetry with neurostimulator 20 to download neurostimulationparameters and, optionally, upload operational or physiological datastored by the neurostimulator. In this manner, the clinician mayperiodically interrogate neurostimulator 20 to evaluate efficacy and, ifnecessary, modifies the stimulation parameters.

Similar to clinician programmer 22, patient programmer 23 may be ahandheld computing device. The patient programmer 23 may also include adisplay and input keys to allow patient 12 to interact with patientprogrammer 23 and implantable neurostimulator 20. In this manner, thepatient programmer 23 provides the patient 12 with an interface forcontrol of neurostimulation therapy by neurostimulator 20. For example,the patient 12 may use patient programmer 23 to start, stop or adjustneurostimulation therapy. In particular, the patient programmer 23 maypermit the patient 12 to adjust stimulation parameters such as duration,amplitude, pulse width and pulse rate, within an adjustment rangespecified by the clinician via the clinician programmer 22.

The neurostimulator 20, clinician programmer 22, and patient programmer23 may communicate via wireless communication, as shown in FIG. 2B. Theclinician programmer 22 and patient programmer 23 may, for example,communicate via wireless communication with neurostimulator 20 using RFtelemetry techniques known in the art. The clinician programmer 22 andpatient programmer 23 also may communicate with each other using any ofa variety of local wireless communication techniques, such as RFcommunication according to the 802.11 or Bluetooth specification sets,or other standard or proprietary telemetry protocols. It is alsounderstood that although FIG. 2B illustrates the patient programmer 23and the clinician programmer 22 as two separate devices, they may beintegrated into a single programmer in some embodiments.

The various aspects of the present disclosure will now be discussed inmore detail below.

FIGS. 2A-2B illustrate the use of the IPG 20 in a spinal cordstimulation context according to some embodiments. In more detail, FIG.2A is a side view of a spine 50, and FIG. 2B is a posterior view of thespine 50. The spine 50 includes a cervical region 51, a thoracic region52, a lumbar region 53, and a sacrococcygeal region 54. The cervicalregion 51 includes the top 7 vertebrae, which may be designated withC1-C7. The thoracic region 52 includes the next 12 vertebrae below thecervical region 51, which may be designated with T1-T12.The lumbarregion 53 includes the final 5 “true” vertebrae, which may be designatedwith L1-L5. The sacrococcygeal region 54 includes 9 fused vertebrae thatmake up the sacrum and the coccyx. The fused vertebrae of the sacrum maybe designated with S1-S5.

Neural tissue (not illustrated for the sake of simplicity) branch offfrom the spinal cord through spaces between the vertebrae. The neuraltissue can be individually and selectively stimulated in accordance withvarious aspects of the present disclosure. For example, referring toFIG. 2B, the IPG device 20 is implanted inside the body. The lead 10 iselectrically coupled to the circuitry inside the IPG device 20. Theconductive lead 10 may be removably coupled to the IPG device 20 througha connector, for example. A distal end of the conductive lead 10 isattached to one or more electrodes 60. The electrodes 60 are implantedadjacent to a desired nerve tissue in the thoracic region 52. Usingwell-established and known techniques in the art, the distal end of thelead 10 with its accompanying electrodes may be positioned along or nearthe epidural space of the spinal cord. It is understood that althoughonly one conductive lead 10 is shown herein for the sake of simplicity,more than one conductive lead 10 and corresponding electrodes 60 may beimplanted and connected to the IPG device 20.

The electrodes 60 deliver current drawn from the current sources in theIPG device 20, therefore generating an electric field near the neuraltissue. The electric field stimulates the neural tissue to accomplishits intended functions. For example, the neural stimulation mayalleviate pain in an embodiment. In other embodiments, a stimulator maybe placed in different locations throughout the body and may beprogrammed to address a variety of problems, including for example butwithout limitation; prevention or reduction of epileptic seizures,weight control or regulation of heart beats.

It is understood that the IPG device 20, the lead 10, and the electrodes60 may be implanted completely inside the body, may be positionedcompletely outside the body or may have only one or more componentsimplanted within the body while other components remain outside thebody. When they are implanted inside the body, the implant location maybe adjusted (e.g., anywhere along the spine 50) to deliver the intendedtherapeutic effects of spinal cord electrical stimulation in a desiredregion of the spine. Furthermore, it is understood that the IPG device20 may be controlled by a patient programmer or a clinician programmer22, the implementation of which may be similar to the clinicianprogrammer shown in FIG. 2B.

FIGS. 3A-3B, 4, 5A-5B, and 6 illustrate various example embodiments ofthe patient pocket programmer (hereinafter referred to as patientprogrammer for simplicity) according to various aspects of the presentdisclosure. In more detail, FIGS. 3A-3B, 4 are directed to a patientprogrammer that is implemented as a pocket controller 104, and FIGS.5A-5B and 6 are directed to a patient programmer that is implemented asa patient programmer charger (PPC) 106.

Referring now to FIGS. 3A and 3B, the pocket controller 104 comprises anouter housing 120 having an on-off switch 122, a user interfacecomprising a plurality of control buttons 124, and a display 126. Inthis embodiment, the housing 120 is sized for discreetness and may besized to fit easily in a pocket and may be about the same size as a keyfob. In one example, the housing 120 forming the pocket controller 104has a thickness of less than about 1.5 inch, a width of less than about1.5 inch, and a height of less than about 3 inches. In another example,the housing 120 forming the pocket controller 104 has a thickness ofabout 0.8 inch, a width of about 1.4 inch, and a height of about 2.56inch. However, both larger and smaller sizes are contemplated.

In this example, the control buttons 124 include two adjustment buttons128 a, 128 b, a select button 130, and an emergency off button (notshown, but disposed on a side of the housing 120 opposing the on-offswitch 122). The two adjustment buttons 128 a, 128 b allow a user toscroll or highlight available options and increase or decrease valuesshown on the display 126. The select button 130 allows a user to enterthe value or select the highlighted options to be adjusted by actuationof the adjustment buttons 128 a, 128 b. In this example, the buttons 128a, 128 b are used to navigate to one of the three availablefunctions: 1) electrical stimulation on/off, 2) control stimulationamplitude adjustment, and 3) electrical stimulation program selection.Once the desired function is highlighted, the select button is pushed toallow changes (i.e. change the stimulation amplitude, select a differentstimulation program, or turn the electrical stimulation on or off). Insome examples, the IPG control functions of the pocket controller 104consist of these functions. The emergency off button is disposed foreasy access for a patient to turn off stimulation from the IPG 102 ifthe IPG provides too much stimulation or stimulation becomesuncomfortable for the patient. Allowing the user to scroll through theplurality of options (also referred to herein as operational parameters)that can be adjusted via the pocket controller 104 provides the user theconfidence to carry only the pocket controller 104 while away from home.Users may be reluctant to carry only a conventional controller thatallows adjustment of only a single operational parameter out of fearthat they may need to adjust a different operational parameter whileaway from a more full-featured controller.

In the embodiment shown, the display 126 is an LCD display arranged toconvey information to the user regarding selectable options, presentsettings, operating parameters and other information about the IPG 102or the pocket controller 104. In this example, the display 126 shows thepocket controller's battery status at 132, the IPG's battery status at134, the IPG's on or off status at 136, the currently selectedelectrical stimulation program at 138, and the amplitude setting of therunning electrical stimulation program at 140. Other types of displaysare also contemplated.

FIG. 4 shows a block diagram of components making up the pocketcontroller 104. It includes a user interface 150, a control module 152,a communication module 154, and a power storing controller 156. The userinterface 150 is comprised of the buttons 128 a, 128 b, 130 and thedisplay 126 described above with reference to FIG. 3A.

As can be seen, the user interface 150 is in communication with thecontrol module 152. The control module 152 comprises a processor 158,memory, an analog-digital converter 162, and a watch dog circuit 164.The processor 158 may include a microprocessor, a controller, a digitalsignal processor (DSP), an application specific integrated circuit(ASIC), a field programmable gate array (FPGA), discrete logiccircuitry, or the like. The processor 158 is configured to execute codeor instructions provided in the memory. Here, the memory is comprised offlash memory 166 and RAM memory 168. However, the memory may include anyvolatile or non-volatile media, such as a random access memory (RAM),read only memory (ROM), non-volatile RAM (NVRAM), electrically erasableprogrammable ROM (EEPROM), flash memory, and the like. In someembodiments, the memory stores sets of stimulation control parametersthat are available to be selected for delivery through the communicationmodule 154 to the IPG 102 for electrical stimulation therapy. The ADconverter 162 performs known functions of converting signals and the WD164 is arranged to time out when necessary, such as in an event wherethe software becomes stuck in a loop. In one embodiment, the controlmodule 152 comprises integrated circuits disposed on a PC board.

The communication module 154 comprises a medical implant communicationservice (MICS) RF transceiver 172 used to communicate with the IPG 102to communicate desired changes and to receive status updates from andrelating to the IPG 102, such as battery status and any errorinformation. As used herein, MICS refers to wireless communications in afrequency band ranging from about 402 MHz to about 405 MHz, which isdedicated for communications with implanted medical devices. In thisexample, the MICS RF transceiver 172 utilizes a loop antenna for thecommunications with the IPG 102. Other antennas, such as, for example,dipole, chip antennas, or other known in the art also may be used. Thecommunication module 154 also includes a wake up transmitter 174, anamplifier 176, and matching networks 178. The wake up transmitter 174operates on a high frequency and is configured to send a short signalburst to wake up the IPG 102 when it is in a power-saving mode. Once theIPG 102 is ready, a communications link can be established between theIPG 102 and pocket controller 104, and communications can then occurover the MICS transceiver 172 using a standard frequency for a medicaldevice transmission. The matching networks 178 tunes the antenna foroptimum transmission power for the frequency selected. The pocketcontroller 104 also includes a programming interface 182. This may beused during manufacturing to load an operating system and program thepocket controller 104.

The power storing controller 156 is configured to convert power torecharge one or more rechargeable batteries 180. The batteries 180provide power to operate the pocket controller 104 allowing it toreceive user inputs and transmit control signals to the IPG 102. Someembodiments use primary cell batteries instead of rechargeablebatteries. As indicated above, this pocket controller 104 is part of alarger system that contains the PPC 106 with a rich feature set forcontrolling the IPG 102 and includes an integrated battery charger usedto charge the IPG's battery. By providing both the pocket controller 104and the PPC 106, the patient can have a small unobtrusive device tocarry around as they go about their daily business and a larger morefull featured device which they can use in the comfort and privacy oftheir homes.

The pocket controller 104 is not only comfortable to carry in a pocket,but can also be attached to a key ring, lanyard, or other such carryingdevice for ease of daily use. Its functions are a subset of functionsfound on the PPC 106, and permit a user to power stimulation from theIPG on and off (i.e., the IPG 102 remains on, but stimulation is toggledbetween the on state when the IPG 102 is emitting electrical pulses andthe off state when the IPG 102 is not emitting electrical pulses butremains in the standby mode for additional communications from thepocket controller 104, the PPC 106, or both), select which electricalstimulation program to run, and globally adjust the amplitude ofelectrical pulses emitted in a series of electrical pulses emitted bythe IPG 102. By limiting the functions of the pocket controller to thosemost commonly used on a daily basis, the device becomes much lessintimidating to the patient, and allows it to be kept very small. Bykeeping the device small, such as about key fob size, it becomesunobtrusive and the patient is more comfortable with having and using animplanted device.

FIGS. 5A-5B show the PPC 106 in greater detail. FIG. 5A is a front viewof the PPC and FIG. 5B is a top view of FIG. 5A. The PPC 106 performsall the same operating functions as the pocket controller 104, butincludes additional operating functions making it a multi-functionfull-featured, advanced patient controller charger. In the embodimentshown, the PPC 106 provides a simple but rich feature set to the moreadvanced user, along with the charging functions.

The PPC 106 includes a controller-charger portion 200 and a coil portion202 connected by a flexible cable 204 and sharing components asdescribed below. The controller-charger portion 200 comprises an outerhousing 206 having an on-off switch 208 on its side, a plurality ofcontrol buttons 210, and a display 212, and an emergency off button (notshown, but disposed on a side of the housing 206 opposing the on-offswitch 208). In this embodiment, the control buttons 210 are icons onthe display 212, and the display is a full color, touch screen,graphical user interface. In addition, the controller-charger portion200 includes a home button 214 configured to return the displayed imagesto a home screen. The controller-charger portion 200 is larger than thepocket controller 104 and in one embodiment is sized with a heightgreater than about 3 inches, a width greater than about 2.5 inches, anda thickness greater than about 0.8 inch. In another embodiment, thecontroller-charger portion is sized with a width of about 3.1 inches, aheight of about 4.5 inches, and thickness of about 0.96 inches, althoughboth larger and smaller sizes are contemplated.

In this example, the control buttons 210 allow a user to select adesired feature for control or further display. Particularly, thecontrol buttons 210 enable functions of the PPC 106 that are the same asthose of the pocket controller 104 (stimulation on/off, programstimulation amplitude adjustment, and stimulation program selection)along with additional features including: charging IPG battery,individual pulse stimulation amplitude adjustment that adjusts anamplitude of an individual pulse relative to the amplitude of anadjacent pulse in a series of pulses emitted by the IPG 102, stimulationprogram frequency adjustment, individual pulse width adjustment,detailed IPG status, detailed PPC status, PPC setup/configuration, a PPCbattery status indicator, PPC to IPG communication status indicator, andother items and functions. The detailed IPG status may include, forexample, IPG serial number and IPG software revision level. Detailed PPCstatus may include, for example, date and time setting, brightnesscontrol, audio volume and mute control, and PPC serial number andsoftware revision level.

By having a pocket controller 104 that is limited to a plurality, suchas only three controls (stimulation on/off, program amplitude adjust,and stimulation program selection), for example, a user can quickly andeasily identify and select the features that are most commonly used.Features that are used less frequently, such as IPG recharge, areincluded on the full-featured PPC, but not the pocket controller 104.Features that are seldom accessed, or not accessed at all by some users,including individual pulse amplitude adjust, pulse width adjust,stimulation program frequency adjust, or serial number and softwarerevision information, are also not included on the limited-featurepocket controller, but are included on the PPC. This allows the pocketcontroller to be significantly smaller, with a very simple and easy touser interface, as compared to systems that need to support all of thesefeatures.

Referring to the example shown in FIG. 5A, the touch screen display 212is arranged to convey information to the user regarding selectableoptions, current settings, operating parameters and other informationabout the IPG 102 or the PPC 106. In this example, the display 212 showsa MICS communication indicator 220, the PPC's battery status at 222, theIPG's battery status at 224, the IPG's on or off status at 226, thecurrently selected electrical stimulation program at 228, and theamplitude setting of the active electrical stimulation program at 230.In addition, the display 212 shows the frequency 232, the pulse widthsetting 234, a selectable status icon for accessing detailed PPCinformation 236, a selectable status icon for accessing detailed IPGinformation 238, and a selectable icon for enabling IPG charging 240.Selecting any single icon may activate another menu within that selectedsubject area. The controller-charger portion 200 may include arechargeable battery whose charge status is shown by the PPC's batterystatus at 222.

The coil portion 202 is configured to wirelessly charge the batteries inthe IPG 102. In use, the coil portion 202 is applied against thepatient's skin or clothing externally so that energy can be inductivelytransmitted and stored in the IPG battery. As noted above, the coilportion 202 is connected with the integrated controller-charger portion200. Accordingly, the controller-charger portion 200 can simultaneouslydisplay the current status of the coil portion 204, the battery powerlevel of the IPG 102, as well as the battery power level of the PPC.Accordingly, controlling and charging can occur in a more simplistic,time-effective manner, where the patient can perform all IPG maintenancein a single sitting. In addition, since the most commonly used featuresof the PPC 106 are already functional on the pocket controller, the PPC106 may be left at home when the user does not desire to carry thelarger, more bulky PPC.

FIG. 6 shows a block diagram of the components making up the PPC 106. Itincludes a user interface 250, a control module 252, a communicationmodule 254, an IPG power charging module 256, and a power storing module258. The user interface 250 is comprised of the buttons 210 and thedisplay 212 described above. In this embodiment however, the userinterface 250 also includes one or more LEDs 266 signifying whether thePPC 106 is charging or powered on and a backlight 268 that illuminatesthe color display. In some embodiments, these LEDs may have colorssymbolizing the occurring function. An LED driver 270 and a speaker oramplifier 272 also form a part of the user interface 250.

As can be seen, the user interface 250 is in communication with thecontrol module 252. The control module 252 comprises a processor 276,memory 278, and a power management integrated circuit (PMIC)/real timeclock (RTC) 280. In the example shown, the control module 252 alsoincludes a Wi-Fi RF transceiver 282 that allows the PPC 106 to connectto a wireless network for data transfer. For example, it may permitdoctor-patient interaction via the internet, remote access to PPC logfiles, remote diagnostics, and other information transfer functions. ThePMIC 280 is configured to control the charging aspects of the PPC 106.The Wi-Fi transceiver 282 enables Wi-Fi data transfer for programmingthe PPC 106, and may permit wireless access to stored data and operatingparameters. Some embodiments also include a Bluetooth RF transceiver forcommunication with, for example, a Bluetooth enabled printer, akeyboard, etc.

In one embodiment, the control module 252 also includes an AD converterand a watch dog circuit as described above with reference to the controlmodule 252. Here, the memory 278 is comprised of flash memory and RAMmemory, but may be other memory as described above. In some embodiments,the processor 276 is an embedded processor running a WinCE operatingsystem (or any real time OS) with the graphics interface 250, and thememory 278 stores sets of stimulation control parameters that areavailable to be selected for delivery through the communication module254 to the IPG 102 for electrical stimulation therapy. In oneembodiment, the control module 252 comprises integrated circuitsdisposed on a PC board.

The communication module 254 comprises a MICS RF transceiver 290, a wakeup transmitter 292, an amplifier 294, and matching networks 296. Thecommunication module 254 may be similar to the communication module 154discussed above, and will not be further described here. The PPC 106also includes a programming interface 298 that may be used duringmanufacturing to load an operating system and program the PPC 106.

The power storing module 258 is configured to convert power to rechargeone or more rechargeable batteries 302. In this embodiment, thebatteries 302 are lithium-ion cells that provide power to operate thePPC 106 allowing it to receive user inputs, transmit control signals to,and charge the IPG 102. The power storing module 258 includes aconnector 304 for connecting to a power source, a power protectiondetection circuit 306 for protecting the PPC from power surges, andlinear power supplies 308 for assisting with the electric transfer tocharge the batteries 302. As can be seen, the control module 252 aidswith the charging and is configured to monitor and send the batterycharge level to the user interface 250 for display. The connector 304connects the PPC, directly or indirectly, to a power source (not shown)such as a conventional wall outlet for receiving electrical current. Insome embodiments, the connector 304 comprises a cradle.

The power charging module 256 communicates with the control module 252and is arranged to magnetically or inductively charge the IPG 102. Inthe embodiments shown, it is magnetically or inductively coupled to theIPG 102 to charge rechargeable batteries on the IPG 102. The chargingmodule 256 includes components in both the controller-charger portion200 and the coil portion 202 (FIGS. 5A-5B). It includes switch boostcircuitry 316, a load power monitor 318, an LSK demodulator 321, a ASKmodulator 322, a current mode transmitter 324, an ADC 326, and coils328. As can be seen, the control module 252 aids with the charging andis configured to monitor and send the IPG battery charge level to theuser interface 250 for display.

In this embodiment, the coils 328 are disposed in the coil portion 202and are configured to create magnetic or inductive coupling withcomponents in the IPG 102. Since the coil portion 202 is integrated withthe controller-charger portion 200, both operate from a single battery302. Accordingly, as can be seen by the circuitry, the battery 302powers the control module 252 and all its associated components. Inaddition, the battery 302 powers the power charging module 256 forrecharging the IPG 102.

Because the coil portion 202 is integrated with the controller-chargerportion 200, the control module 252 provides a single control interfaceand a single user interface for performing both functions of controllingthe IPG 102 and of charging the IPG 102. In addition, because thecontroller-charger portion 200 and the coil portion 202 are integrated,the controller-charger portion 200 simultaneously controls both thecurrent status of the charger, the battery power level of the IPG 102,as well as the battery power level of the PPC. Accordingly, controllingand charging can occur in a more simplistic, time-effective manner,where the patient can perform all IPG maintenance in a single sitting.In addition, since the most commonly used features of the PPC 106 arealready functional on the pocket controller, the PPC 106 may be left athome when the user does not desire to carry the larger, more bulky PPC.

FIG. 7 shows a block diagram of one example embodiment of a clinicianprogrammer (CP), for example the CP 22 shown in FIG. 2B. The CP 22includes a printed circuit board (“PCB”) that is populated with aplurality of electrical and electronic components that provide power,operational control, and protection to the CP 22. With reference to FIG.7, the CP includes a processor 300. The processor 300 is a controllerfor controlling the CP 22 and, indirectly, the IPG 20 as discussedfurther below. In one construction, the processor 300 is an applicationsprocessor model i.MX515 available from Freescale Semiconductor. Morespecifically, the i.MX515 applications processor has internalinstruction and data cashes, multimedia capabilities, external memoryinterfacing, and interfacing flexibility. Further information regardingthe i.MX515 applications processor can be found in, for example, the“IMX510EC, Rev. 4” data sheet; dated August 2010; published by FreescaleSemiconductor at www.freescale.com, the content of the data sheet beingincorporated herein by reference. Of course, other processing units,such as other microprocessors, microcontrollers, digital signalprocessors, etc., can be used in place of the processor 300.

The CP 22 includes memory, which can be internal to the processor 300(e.g., memory 305), external to the processor 300 (e.g., memory 310), ora combination of both. Exemplary memory include a read-only memory(“ROM”), a random access memory (“RAM”), an electrically erasableprogrammable read-only memory (“EEPROM”), a flash memory, a hard disk,or another suitable magnetic, optical, physical, or electronic memorydevice. The processor 300 executes software that is capable of beingstored in the RAM (e.g., during execution), the ROM (e.g., on agenerally permanent basis), or another non-transitory computer readablemedium such as another memory or a disc. The CP 22 also includesinput/output (“I/O”) systems that include routines for transferringinformation between components within the processor 300 and othercomponents of the CP 22 or external to the CP 22.

Software included in the implementation of the CP 22 is stored in thememory 305 of the processor 300, memory 310 (e.g., RAM or ROM), orexternal to the CP 22. The software includes, for example, firmware, oneor more applications, program data, one or more program modules, andother executable instructions. The processor 300 is configured toretrieve from memory and execute, among other things, instructionsrelated to the control processes and methods described below for the CP22. For example, the processor 300 is configured to execute instructionsretrieved from the memory 140 for establishing a protocol to control theIPG 20.

One memory shown in FIG. 7 is memory 310, which can be a double datarate (DDR2) synchronous dynamic random access memory (SDRAM) for storingdata relating to and captured during the operation of the CP 22. Inaddition, a secure digital (SD) multimedia card (MMC) can be coupled tothe CP for transferring data from the CP to the memory card via slot315. Of course, other types of data storage devices can be used in placeof the data storage devices shown in FIG. 7.

The CP 22 includes multiple bi-directional radio communicationcapabilities. Specific wireless portions included with the CP 22 are aMedical Implant Communication Service (MICS) bi-direction radiocommunication portion 320, a Wi-Fi bi-direction radio communicationportion 325, and a Bluetooth bi-direction radio communication portion330. The MICS portion 320 includes a MICS communication interface, anantenna switch, and a related antenna, all of which allows wirelesscommunication using the MICS specification. The Wi-Fi portion 325 andBluetooth portion 330 include a Wi-Fi communication interface, aBluetooth communication interface, an antenna switch, and a relatedantenna all of which allows wireless communication following the Wi-FiAlliance standard and Bluetooth Special Interest Group standard. Ofcourse, other wireless local area network (WLAN) standards and wirelesspersonal area networks (WPAN) standards can be used with the CP 22.

The CP 22 includes three hard buttons: a “home” button 335 for returningthe CP to a home screen for the device, a “quick off” button 340 forquickly deactivating stimulation IPG, and a “reset” button 345 forrebooting the CP 22. The CP 22 also includes an “ON/OFF” switch 350,which is part of the power generation and management block (discussedbelow).

The CP 22 includes multiple communication portions for wiredcommunication. Exemplary circuitry and ports for receiving a wiredconnector include a portion and related port for supporting universalserial bus (USB) connectivity 355, including a Type-A port and a Micro-Bport; a portion and related port for supporting Joint Test Action Group(JTAG) connectivity 360, and a portion and related port for supportinguniversal asynchronous receiver/transmitter (UART) connectivity 365. Ofcourse, other wired communication standards and connectivity can be usedwith or in place of the types shown in FIG. 7.

Another device connectable to the CP 22, and therefore supported by theCP 22, is an external display. The connection to the external displaycan be made via a micro High-Definition Multimedia Interface (HDMI) 370,which provides a compact audio/video interface for transmittinguncompressed digital data to the external display. The use of the HDMIconnection 370 allows the CP 22 to transmit video (and audio)communication to an external display. This may be beneficial insituations where others (e.g., the surgeon) may want to view theinformation being viewed by the healthcare professional. The surgeontypically has no visual access to the CP 22 in the operating room unlessan external screen is provided. The HDMI connection 370 allows thesurgeon to view information from the CP 22, thereby allowing greatercommunication between the clinician and the surgeon. For a specificexample, the HDMI connection 370 can broadcast a high definitiontelevision signal that allows the surgeon to view the same informationthat is shown on the LCD (discussed below) of the CP 22.

The CP 22 includes a touch screen I/O device 375 for providing a userinterface with the clinician. The touch screen display 375 can be aliquid crystal display (LCD) having a resistive, capacitive, or similartouch-screen technology. It is envisioned that multitouch capabilitiescan be used with the touch screen display 375 depending on the type oftechnology used.

The CP 22 includes a camera 380 allowing the device to take pictures orvideo. The resulting image files can be used to document a procedure oran aspect of the procedure. For example, the camera 380 can be used totake pictures of barcodes associated with the IPG 20 or the leads, ordocumenting an aspect of the procedure, such as the positioning of theleads. Similarly, it is envisioned that the CP 22 can communicate with afluoroscope or similar device to provide further documentation of theprocedure. Other devices can be coupled to the CP 22 to provide furtherinformation, such as scanners or RFID detection. Similarly, the CP 22includes an audio portion 385 having an audio codec circuit, audio poweramplifier, and related speaker for providing audio communication to theuser, such as the clinician or the surgeon.

The CP 22 further includes a power generation and management block 390.The power generation and management block 390 has a power source (e.g.,a lithium-ion battery) and a power supply for providing multiple powervoltages to the processor, LCD touch screen, and peripherals.

FIG. 8 shows a block diagram of an example embodiment of an IPG, forexample an embodiment of the IPG 20 shown in FIG. 2B. The IPG 20includes a printed circuit board (“PCB”) that is populated with aplurality of electrical and electronic components that provide power,operational control, and protection to the IPG 20. With reference toFIG. 8, the IPG 20 includes a communication portion 400 having atransceiver 405, a matching network 410, and antenna 412. Thecommunication portion 400 receives power from a power ASIC (discussedbelow), and communicates information to/from the microcontroller 415 anda device (e.g., the CP 22) external to the IPG 20. For example, the IPG20 can provide bi-direction radio communication capabilities, includingMedical Implant Communication Service (MICS) bi-direction radiocommunication following the MICS specification.

The IPG 20, as previously discussed, provides stimuli to electrodes ofan implanted medical electrical lead 110. As shown in FIG. 8, 1-Nelectrodes are connected to the IPG 20. In addition, the enclosure orhousing 420 of the IPG 20 can act as an electrode. The stimuli areprovided by a stimulation portion 425 in response to commands from themicrocontroller 415. The stimulation portion 425 includes a stimulationapplication specific integrated circuit (ASIC) 430 and circuitryincluding blocking capacitors and an over-voltage protection circuit. Asis well known, an ASIC is an integrated circuit customized for aparticular use, rather than for general purpose use. ASICs often includeprocessors, memory blocks including ROM, RAM, EEPROM, Flash, etc. Thestimulation ASIC 430 can include a processor, memory, and firmware forstoring preset pulses and protocols that can be selected via themicrocontroller 415. The providing of the pulses to the electrodes iscontrolled through the use of a waveform generator and amplitudemultiplier of the stimulation ASIC 430, and the blocking capacitors andovervoltage protection circuitry of the stimulation portion 425, as isknown in the art. The stimulation portion 425 of the IPG 20 receivespower from the power ASIC (discussed below). The stimulation ASIC 430also provides signals to the microcontroller 415. More specifically, thestimulation ASIC 430 can provide impedance values for the channelsassociated with the electrodes, and also communicate calibrationinformation with the microcontroller 415 during calibration of the IPG20.

The IPG 20 also includes a power supply portion 440. The power supplyportion includes a rechargeable battery 445, fuse 450, power ASIC 455,recharge coil 460, rectifier 463 and data modulation circuit 465. Therechargeable battery 445 provides a power source for the power supplyportion 440. The recharge coil 460 receives a wireless signal from thePPC 135. The wireless signal includes an energy that is converted andconditioned to a power signal by the rectifier 463. The power signal isprovided to the rechargeable battery 445 via the power ASIC 455. Thepower ASIC 455 manages the power for the IPG 20. The power ASIC 455provides one or more voltages to the other electrical and electroniccircuits of the IPG 155. The data modulation circuit 465 controls thecharging process.

The IPG also includes a sensor section 470 that includes a thermistor475, an accelerometer 478, and a magnetic sensor 480. The thermistor 475detects temperature of the IPG. The accelerometer 478 detects motion ormovement of the IPG, and the magnetic sensor 480 provides a “hard”switch upon sensing a magnet for a defined period. The signal from themagnetic sensor 480 can provide an override for the IPG 20 if a fault isoccurring with the IPG 20 and is not responding to other controllers.The magnetic sensor 480 can also be used to turn on and off stimulation.

The IPG 20 is shown in FIG. 8 as having a microcontroller 415. Generallyspeaking, the microcontroller 415 is a controller for controlling theIPG 20. The microcontroller 415 includes a suitable programmable portion481 (e.g., a microprocessor or a digital signal processor), a memory482, and a bus or other communication lines. An exemplarymicrocontroller capable of being used with the IPG is a model MSP430ultra-low power, mixed signal processor by Texas Instruments. Morespecifically, the MSP430 mixed signal processor has internal RAM andflash memories, an internal clock, and peripheral interfacecapabilities. Further information regarding the MSP 430 mixed signalprocessor can be found in, for example, the “MSP430G2x32, MSP430G2x02MIXED SIGNAL MICROCONTROLLER” data sheet; dated December 2010, publishedby Texas Instruments at www.ti.com; the content of the data sheet beingincorporated herein by reference.

The IPG 20 includes memory, which can be internal to the control device(such as memory 482), external to the control device (such as serialmemory 495), or a combination of both. Exemplary memory include aread-only memory (“ROM”), a random access memory (“RAM”), anelectrically erasable programmable read-only memory (“EEPROM”), a flashmemory, a hard disk, or another suitable magnetic, optical, physical, orelectronic memory device. The programmable portion 481 executes softwarethat is capable of being stored in the RAM (e.g., during execution), theROM (e.g., on a generally permanent basis), or another non-transitorycomputer readable medium such as another memory or a disc.

Software included in the implementation of the IPG 20 is stored in thememory 482. The software includes, for example, firmware, one or moreapplications, program data, one or more program modules, and otherexecutable instructions. The programmable portion 481 is configured toretrieve from memory and execute, among other things, instructionsrelated to the control processes and methods described below for the IPG20. For example, the programmable portion 481 is configured to executeinstructions retrieved from the memory 482 for sweeping the electrodesin response to a signal from the CP 22.

The PCB also includes a plurality of additional passive and activecomponents such as resistors, capacitors, inductors, integratedcircuits, and amplifiers. These components are arranged and connected toprovide a plurality of electrical functions to the PCB including, amongother things, filtering, signal conditioning, or voltage regulation, asis commonly known.

FIG. 9 is a block diagram of an exemplary handheld patient feedbackdevice or patient feedback tool (hereinafter interchangeably referred toas PFD or PFT) 500 for use in a neurostimulation system, and FIGS. 10Aand 10B are diagrammatic illustrations of the PFT 500 according tovarious example embodiments. With reference to FIGS. 9 and 10A-10B, thePFT 500 includes a housing 502 which may have one or more of a sensor, acontroller, and/or a communication port connected thereto. Theconstruction of the PFT 500 shown in FIG. 9 includes two inputs 504 and505 in communication with the housing 502 of the device 500 and oneinput 510 internal to the housing 502. One of the external inputs 504 isa binary ON/OFF switch, for example activated by the patient's thumb, toallow the patient to immediately deactivate stimulation. Input 504 maybe coupled to the controller 525 via electrostatic discharge (ESD)protection and/or debouncing circuits. The second input 505 includes aforce sensor sensing the pressure or force exerted by the patient'shand. Input/sensor 505 may be coupled to the controller 525 via ESDprotection, signal conditioning, and/or signal amplification circuits.The sensed parameter can be either isotonic (constant force, measuringthe distance traversed) or isometric (measured force, proportional topressure applied by patient). The resulting signal from the sensor 505is analog and, therefore, after the signal is conditioned and/oramplified, it can be passed to microcontroller 525 via ananalog-to-digital converter.

The internal input 510 for the PFT 500 may be a motion sensor. Thesensor 510, upon detecting motion, initiates activation of the PFT 500.The device 500 stays active until movement is not detected by the sensor510 for a time period, which in various constructions may be between onesecond and five minutes. Power is provided by an internal battery 520that can be replaceable and/or rechargeable, which in variousconstructions has an approximately three hour life under continuous use.As discussed below, a motion sensor such as sensor 510 can also be usedto obtain feedback from the patient regarding paresthesia.

The processing of the inputs from the sensors 504 and 505 takes place ina controller, such as a microcontroller 525. An exemplarymicrocontroller capable of being used with the invention ismicrocontroller 525, which includes a suitable programmable portion 530(e.g., a microprocessor or a digital signal processor), a memory 535,and a bus 540 or other communication lines. Output data of themicrocontroller 525 is sent via a Bluetooth bi-direction radiocommunication port 545 to the CP (clinician programmer). The Bluetoothportion 545 includes a Bluetooth communication interface, an antennaswitch, and a related antenna, all of which allows wirelesscommunication following the Bluetooth Special Interest Group standard.Other forms of wired and wireless communication between the PFT 500 andother components of the system including the CP are also possible. Otheroutputs may include indicators (such as light-emitting diodes) forcommunicating stimulation activity 550, sensor activation 555, devicepower 560, and battery status 565.

The housing 502 of the PFT 500 may be cylindrical in shape, and in oneparticular construction the cylinder is approximately 35 mm in diameterand 80 mm in length. In other constructions the cylinder is larger orsmaller in diameter and/or length, for example in order to accommodatehands of varying sizes. In various constructions the diameter can rangefrom 20 to 50 mm and the length from 30 to 120 mm, although other sizesabove and below these ranges are also possible.

Furthermore, the shape of the PFT 500 can be other than a circularcross-section, for example oval, square, hexagonal, or other shape.Still further, the cross-section of the PFT 500 can vary along itslength, for example being cylindrical in some portions and oval, square,hexagonal or other shape(s) in other portions. In yet otherconstructions, the PFT 500 has a spherical, toroid, or other shape.

The housing 502 may be made from a resilient material such as rubber orplastic with one or more sensors 505 coupled to or supported by thehousing 502. The manner in which the sensor 505 is coupled to thehousing 502 depends on the type of sensor that is employed, as discussedbelow. Thus, when the patient applies a force to the housing 502, thesensor 505 generates a signal that generally is proportional to thedegree of force applied. Although the discussion herein mentions thepatient using his or her hand to generate force to squeeze the housing502 of the PFT 500, in various constructions the patient may instead useother body parts, such as the mouth or foot, to generate force. Moregenerally, the patient can generate feedback by a physical action,usually a force applied by the hand or other body part, but the physicalaction can include other movements, such as movement of the patient'seyes, head, or hands, to generate a feedback signal.

After the signal is generated, it is transmitted from the sensor 505 tothe controller 525. The controller 525 processes the signal and, basedon one or more such signals from the sensor 505, the controller 525generates another signal that is to be transmitted to the CP. Thecontroller 525 sends the signal to be transmitted to the communicationport 545 of the PFT 500 from which it is then transmitted to the CP orother external device. As discussed further below, the signal can betransmitted from the communication port 545 to the CP using variouswired or wireless methods of communication.

In various constructions, an isotonic force sensor may include a sensorthat measures the distance traveled by the sensor with relativelyconstant force applied by the patient. Isotonic force sensors mayinclude a trigger 570 (See FIG. 10A) or other lever mechanism coupled toa wiper 572 that moves along a rheostat 574 or across a series ofdetectors. Exemplary detectors include electrical contacts or opticaldetectors, such as photodiodes. In other constructions, an isometricforce sensor may include a strain gauge, a piezoelectric device, or apressure sensor, each of which measures force that is proportional tothe pressure applied to the PFT 500 by the patient, generally with onlya small amount of travel or shape change to the sensor.

Both the isotonic and isometric sensors generate an electrical signalthat is proportional to the force that is applied to the sensor. Anisometric force sensor may be incorporated into a relatively stiffobject such that only slight deformation of the object is needed toregister a change in force. In still other constructions, the forcesensor may include a combination of elements, such as a trigger or otherlever that experiences increasing resistance or pressure as the traveldistance increases. For example, increasing resistance or pressure canbe created by attaching a relatively stiff spring to the lever or wipermechanism to increase resistance as the lever or wiper is moved.

In some constructions (e.g. as shown in FIG. 10B), the PFT 500 includesa feedback mechanism 580 that indicates to the patient the amount offorce that is detected by the force sensor 505. The feedback mechanism580 may include one or more of a visual, audible, or tactile feedbackmechanism that is used to indicate to the patient the degree to whichthe sensor 505 has been activated, e.g., how much force has been appliedor how much the lever or wiper mechanism has traveled. The feedbackmechanism gives the patient a sense of whether their activation of thesensor 505 is being detected at what the patient feels is the correctlevel and to give the patient a means to make their activation of thesensor 505 more consistent.

Visual feedback mechanisms 580 can include a series of lights (e.g.LEDs) or a digital readout (e.g. a numerical display); audible feedbackcan include sounds that vary in amplitude (volume) and/or tone; andtactile feedback mechanisms can include vibration of the PFT 500 and/oraltering the shape of the surface of the PFT 500 (e.g. raising of one ormore structures such as dots to form Braille-type patterns) in alocation that is capable of contacting the patient's skin. Using acombination of feedback modalities will benefit patients who havesensory impairments, including, e.g., impaired hearing and/or sight.

The feedback can include a semi-quantitative indication of the patient'sresponse, e.g. including a variety of (e.g. 1-5 or 1-10) intensitylevels to indicate a relative degree of force applied by the patient.The patient will then be able to see, hear, and/or feel the level offorce that is sensed by the sensor 505 of the PFT 500, to help thepatient confirm that their response to the stimulus was received, aswell as the degree of response that was registered. The correlationbetween the level of force applied and the output of the feedbackmechanism 580 can be calibrated separately for each patient during aninitial calibration session.

To facilitate gripping of the PFT 500, the housing 502, in certainconstructions, may be covered with one or more surfaces, textures, ormaterials to improve grip, such as grooves, stipples, indentations,rubber, or plastic, and may include a wrist strap 582 to keep the PFT500 from falling if it is dropped by the patient.

The PFT 500, in some constructions, may also include a connectionfeedback mechanism, particularly where the PFT 500 is in wirelesscommunication with the CP. The connection feedback mechanism can includeone or more of a visual, audible, or tactile mechanism to inform thepatient and/or medical personnel of whether the PFT 500 is maintaining aconnection with the CP, the strength of the connection, and/or if theconnection has been lost. For example, the PFT 500 may emit a signal(e.g., light, sound, and/or tactile) at regular (e.g., one minute)intervals to confirm that communication is still maintained.

Conversely, the PFT 500 may emit such a signal only if communication islost. In some constructions, the PFT 500 may tolerate brief intervals inwhich the signal is lost (e.g., a predetermined time, generally between0.1-100 sec) before the patient is warned of a possible lost connection.In various constructions, the controller 525 of the PFT 500 includesmemory that permits buffering of a limited amount of data, which can beused to accumulate data prior to sending to the CP and which can holddata during brief intervals in which the connection is lost. In variousconstructions, if communication between the PFT 500 and the CP is lostfor more than a predetermined interval of time, then the CP stopsstimulation of electrodes until a connection with the PFT 500 isreestablished.

Thus, according to various constructions, the PFT 500 may include one ormore of: a sound generating mechanism 584 (e.g., a speaker); a tactilemechanism 586 such as a vibration device and/or a mechanism for creatinga raised pattern; a digital numerical readout 588 (e.g., LED or LCDdisplay); and one or more indicator lights 590 (e.g., a series of LEDs);which may be employed to provide feedback to the patient regarding theforce being applied and/or communication status.

Various types of sensing mechanisms can be used for the sensor 505,which would depend in part on the type of housing 502 that is used withthe PFT 500. For example, if the housing 502 is a sealed, flexiblecompartment (e.g., a ball or other object filled with gel, air, orliquid) a piezoelectric-based pressure sensing mechanism can be used asthe sensor 505 in order to measure changes in pressure when the patientsqueezes or relaxes his/her grip on the PFT 500. Alternatively, arheostat 574 or other linear sensing mechanism can be used with a pistolgrip style PFT 500 design (FIG. 10A), where a trigger 570 is coupled toa wiper 572 that moves across the rheostat 574 or other linear sensor.

FIGS. 11A-11C illustrate other embodiments of the PFT for receivingpatient feedback. More specifically, FIG. 11A shows a mouth-piece 620that is inserted into the mouth of the patient. The user providesfeedback by biting the mouthpiece. FIG. 11B shows an optical sensor 630(such as a camera and related image processing software) that detectsvisual cues from a patient. An example visual cue may be the blinking ofthe patient's eyes. FIG. 11C shows a foot pedal 640 that receives inputthrough the patient's manipulation of a switch and/or sensor with hisfoot. In some constructions, the PFT 500 includes one or moreaccelerometers (such as the motion sensor 510), and the patient providesfeedback by moving the PFT 500 in various distinct patterns that arerecognized by the controller 525 of the PFT 500 or by the CP.

It is also envisioned that the patient may provide feedback directly tothe CP. In various constructions, the patient is trained to use theparticular feedback device (e.g. the PFT 500 or the CP as applicable) inorder to properly inform the CP of the patient's reaction to stimuli asthey are applied to the IPG in the patient. In particular constructions,the CP is programmed to learn the patient's response times and/or themagnitude of the patient's responses in order to obtain a profile of thepatient's reaction to various stimuli, as discussed above.

Referring now to FIG. 12, a simplified block diagram of a medicalinfrastructure 800 (which may also be considered a medical system) isillustrated according to various aspects of the present disclosure. Themedical infrastructure 800 includes a plurality of medical devices 810.These medical devices 810 may each be a programmable medical device (orparts thereof) that can deliver a medical therapy to a patient. In someembodiments, the medical devices 810 may include a device of theneurostimulator system discussed above. For example, the medical devices810 may be a pulse generator (e.g., the IPG discussed above), animplantable lead, a charger, or portions thereof. It is understood thateach of the medical devices 810 may be a different type of medicaldevice. In other words, the medical devices 810 need not be the sametype of medical device.

The medical infrastructure 800 also includes a plurality of electronicprogrammers 820. For sake of illustration, one of these electronicprogrammers 820A is illustrated in more detail and discussed in detailbelow. Nevertheless, it is understood that each of the electronicprogrammers 820 may be implemented similar to the electronic programmer820A.

In some embodiments, the electronic programmer 820A may be a clinicianprogrammer, for example the clinician programmer discussed above withreference to FIGS. 2B and 7. In other embodiments, the electronicprogrammer 820A may be a patient programmer discussed above withreference to FIGS. 2B-6. In further embodiments, it is understood thatthe electronic programmer may be a tablet computer. In any case, theelectronic programmer 820A is configured to program the stimulationparameters of the medical devices 810 so that a desired medical therapycan be delivered to a patient.

The electronic programmer 820A contains a communications component 830that is configured to conduct electronic communications with externaldevices. For example, the communications device 830 may include atransceiver. The transceiver contains various electronic circuitrycomponents configured to conduct telecommunications with one or moreexternal devices. The electronic circuitry components allow thetransceiver to conduct telecommunications in one or more of the wired orwireless telecommunications protocols, including communicationsprotocols such as IEEE 802.11 (Wi-Fi), IEEE 802.15 (Bluetooth), GSM,CDMA, LTE, WIMAX, DLNA, HDMI, Medical Implant Communication Service(MICS), etc. In some embodiments, the transceiver includes antennas,filters, switches, various kinds of amplifiers such as low-noiseamplifiers or power amplifiers, digital-to-analog (DAC) converters,analog-to-digital (ADC) converters, mixers, multiplexers anddemultiplexers, oscillators, and/or phase-locked loops (PLLs). Some ofthese electronic circuitry components may be integrated into a singlediscrete device or an integrated circuit (IC) chip.

The electronic programmer 820A contains a touchscreen component 840. Thetouchscreen component 840 may display a touch-sensitive graphical userinterface that is responsive to gesture-based user interactions. Thetouch-sensitive graphical user interface may detect a touch or amovement of a user's finger(s) on the touchscreen and interpret theseuser actions accordingly to perform appropriate tasks. The graphicaluser interface may also utilize a virtual keyboard to receive userinput. In some embodiments, the touch-sensitive screen may be acapacitive touchscreen. In other embodiments, the touch-sensitive screenmay be a resistive touchscreen.

It is understood that the electronic programmer 820A may optionallyinclude additional user input/output components that work in conjunctionwith the touchscreen component 840 to carry out communications with auser. For example, these additional user input/output components mayinclude physical and/or virtual buttons (such as power and volumebuttons) on or off the touch-sensitive screen, physical and/or virtualkeyboards, mouse, track balls, speakers, microphones, light-sensors,light-emitting diodes (LEDs), communications ports (such as USB or HDMIports), joy-sticks, etc.

The electronic programmer 820A contains an imaging component 850. Theimaging component 850 is configured to capture an image of a targetdevice via a scan. For example, the imaging component 850 may be acamera in some embodiments. The camera may be integrated into theelectronic programmer 820A. The camera can be used to take a picture ofa medical device, or scan a visual code of the medical device, forexample its barcode or Quick Response (QR) code.

The electronic programmer contains a memory storage component 860. Thememory storage component 860 may include system memory, (e.g., RAM),static storage (e.g., ROM), or a disk drive (e.g., magnetic or optical),or any other suitable types of computer readable storage media. Forexample, some common types of computer readable media may include floppydisk, flexible disk, hard disk, magnetic tape, any other magneticmedium, CD-ROM, any other optical medium, RAM, PROM, EPROM, FLASH-EPROM,any other memory chip or cartridge, or any other medium from which acomputer is adapted to read. The computer readable medium may include,but is not limited to, non-volatile media and volatile media. Thecomputer readable medium is tangible, concrete, and non-transitory.Logic (for example in the form of computer software code or computerinstructions) may be encoded in such computer readable medium. In someembodiments, the memory storage component 860 (or a portion thereof) maybe configured as a local database capable of storing electronic recordsof medical devices and/or their associated patients.

The electronic programmer contains a processor component 870. Theprocessor component 870 may include a central processing unit (CPU), agraphics processing unit (GPU) a micro-controller, a digital signalprocessor (DSP), or another suitable electronic processor capable ofhandling and executing instructions. In various embodiments, theprocessor component 870 may be implemented using various digital circuitblocks (including logic gates such as AND, OR, NAND, NOR, XOR gates,etc.) along with certain software code. In some embodiments, theprocessor component 870 may execute one or more sequences computerinstructions contained in the memory storage component 860 to performcertain tasks.

It is understood that hard-wired circuitry may be used in place of (orin combination with) software instructions to implement various aspectsof the present disclosure. Where applicable, various embodimentsprovided by the present disclosure may be implemented using hardware,software, or combinations of hardware and software. Also, whereapplicable, the various hardware components and/or software componentsset forth herein may be combined into composite components comprisingsoftware, hardware, and/or both without departing from the spirit of thepresent disclosure. Where applicable, the various hardware componentsand/or software components set forth herein may be separated intosub-components comprising software, hardware, or both without departingfrom the scope of the present disclosure. In addition, where applicable,it is contemplated that software components may be implemented ashardware components and vice-versa.

It is also understood that the electronic programmer 820A is notnecessarily limited to the components 830-870 discussed above, but itmay further include additional components that are used to carry out theprogramming tasks. These additional components are not discussed hereinfor reasons of simplicity. It is also understood that the medicalinfrastructure 800 may include a plurality of electronic programmerssimilar to the electronic programmer 820A discussed herein, but they arenot illustrated in FIG. 12 for reasons of simplicity.

The medical infrastructure 800 also includes an institutional computersystem 890. The institutional computer system 890 is coupled to theelectronic programmer 820A. In some embodiments, the institutionalcomputer system 890 is a computer system of a healthcare institution,for example a hospital. The institutional computer system 890 mayinclude one or more computer servers and/or client terminals that mayeach include the necessary computer hardware and software for conductingelectronic communications and performing programmed tasks. In variousembodiments, the institutional computer system 890 may includecommunications devices (e.g., transceivers), user input/output devices,memory storage devices, and computer processor devices that may sharesimilar properties with the various components 830-870 of the electronicprogrammer 820A discussed above. For example, the institutional computersystem 890 may include computer servers that are capable ofelectronically communicating with the electronic programmer 820A throughthe MICS protocol or another suitable networking protocol.

The medical infrastructure 800 includes a database 900. In variousembodiments, the database 900 is a remote database—that is, locatedremotely to the institutional computer system 890 and/or the electronicprogrammer 820A. The database 900 is electronically or communicatively(for example through the Internet) coupled to the institutional computersystem 890 and/or the electronic programmer. In some embodiments, thedatabase 900, the institutional computer system 890, and the electronicprogrammer 820A are parts of a cloud-based architecture. In that regard,the database 900 may include cloud-based resources such as mass storagecomputer servers with adequate memory resources to handle requests froma variety of clients. The institutional computer system 890 and theelectronic programmer 820A (or their respective users) may both beconsidered clients of the database 900. In certain embodiments, thefunctionality between the cloud-based resources and its clients may bedivided up in any appropriate manner. For example, the electronicprogrammer 820A may perform basic input/output interactions with a user,but a majority of the processing and caching may be performed by thecloud-based resources in the database 900. However, other divisions ofresponsibility are also possible in various embodiments.

According to the various aspects of the present disclosure, varioustypes of data may be uploaded from the electronic programmer 820A to thedatabase 900. The data saved in the database 900 may thereafter bedownloaded by any of the other electronic programmers 820B-820Ncommunicatively coupled to it, assuming the user of these programmershas the right login permissions.

The database 900 may also include a manufacturer's database in someembodiments. It may be configured to manage an electronic medical deviceinventory, monitor manufacturing of medical devices, control shipping ofmedical devices, and communicate with existing or potential buyers (suchas a healthcare institution). For example, communication with the buyermay include buying and usage history of medical devices and creation ofpurchase orders. A message can be automatically generated when a client(for example a hospital) is projected to run out of equipment, based onthe medical device usage trend analysis done by the database. Accordingto various aspects of the present disclosure, the database 900 is ableto provide these functionalities at least in part via communication withthe electronic programmer 820A and in response to the data sent by theelectronic programmer 820A. These functionalities of the database 900and its communications with the electronic programmer 820A will bediscussed in greater detail later.

The medical infrastructure 800 further includes a manufacturer computersystem 910. The manufacturer computer system 910 is also electronicallyor communicatively (for example through the Internet) coupled to thedatabase 900. Hence, the manufacturer computer system 910 may also beconsidered a part of the cloud architecture. The computer system 910 isa computer system of medical device manufacturer, for example amanufacturer of the medical devices 810 and/or the electronic programmer820A.

In various embodiments, the manufacturer computer system 910 may includeone or more computer servers and/or client terminals that each includesthe necessary computer hardware and software for conducting electroniccommunications and performing programmed tasks. In various embodiments,the manufacturer computer system 910 may include communications devices(e.g., transceivers), user input/output devices, memory storage devices,and computer processor devices that may share similar properties withthe various components 830-870 of the electronic programmer 820Adiscussed above. Since both the manufacturer computer system 910 and theelectronic programmer 820A are coupled to the database 900, themanufacturer computer system 910 and the electronic programmer 820A canconduct electronic communication with each other.

After an implantable lead (e.g., lead 10 discussed above with referenceto FIGS. 2A-2B) has been placed inside the patient, an electronicprogrammer (e.g., the clinician programmer 22 discussed above withreference to FIG. 7) may be used to program a pulse generator (e.g., IPG20 discussed above with reference to FIG. 8) to deliver electricalstimulation to the patient through the lead. According to the variousaspects of the present disclosure, the pulse generator herein is capableof generating a unique stimulation waveform. For example, unlikeconventional neurostimulation waveforms that have periodic pulses (e.g.,at a fixed frequency), the pulse generator of the present disclosure cangenerate a stimulation waveform 1000 that has a paresthesia-inducinglow-frequency component and a spread-spectrum non-paresthesia inducinghigh-frequency component. These components are illustrated in both FIG.13 and FIG. 14 below, where FIG. 13 illustrates a portion of thewaveform 1000 in a time domain, and FIG. 14 illustrates a portion of thewaveform 1000 in a frequency domain.

Referring to FIG. 13, three example spread-spectrum pulses (alsoreferred to as sub-tonic pulses) are illustrated in the time domain asspread-spectrum pulses 1001, 1002, and 1003, where of the pulses eachhave a respective stimulation phase and a respective recovery phase. Therecovery phases are shown as being active recovery, but passive recoveryis also possible. In addition, although each of the spread-spectrumpulses has its own recovery phase in the embodiment of FIG. 13, it isunderstood that multiple spread-spectrum pulses may collectively have asingle recovery phase in other embodiments. For example, if there are 20spread-spectrum pulses between a pair of tonic pulses, the 20spread-spectrum pulses may have a single recovery phase (which may beactive recovery or passive recovery) after the active stimulation phasefor all 20 of the spread-spectrum pulses has occurred, or there may be afirst recovery phase after the stimulation phase for the first 10 of the20 spread-spectrum pulses has occurred, and a second recovery phaseafter the stimulation phase for the second 10 of the 20 spread-spectrumpulses has occurred, or there may be a recovery phase after theoccurrence of the stimulation phase for each of the 20 spread-spectrumpulses.

The spread-spectrum nature of the pulses may manifest itself as jitterin the time domain. For example, the periods between pulses are notconstant, but they have varying values. A period may be defined as theamount of elapsed time between the rising edges of adjacent pulses inthe stimulation phase (or alternatively, the falling edges of adjacentpulses in the stimulation phase). In this example, a period (e.g., atime interval) 1010 between pulses 1001 and 1002 is different in valuefrom a period 1011 between pulses 1002 and 1003. For example, the period1010 may have a value of 0.2 milli-seconds (ms), while the period 1011may have a value of 0.15 ms. Of course, these values are merelyexamples, and it is understood that other values are implemented indifferent embodiments. In addition, although the elements 1010 and 1011are each referred to as “period” or “time period”, it is understood thatthey do not have a periodic occurrence or pattern, as discussed in moredetail below.

In some embodiments, the varying of the time periods (e.g., the periods1010 and 1011) between adjacent spread-spectrum pulses is performedusing a pseudo-random number generator, which could be a module insidethe IPG 20 or alternatively in the clinician programmer 22. Based on oneor more seed values, the pseudo-random number generator is configured togenerate a series of pseudo-random values whose properties approximatethe properties of sequences of truly random numbers. In someembodiments, the series of pseudo-random values are in a predefinedrange, for example in a range between X and Y, where X and Y are valuescorresponding to the time period (e.g., the period 1010) between twoadjacent spread spectrum pulses. In this manner, after one of the spreadspectrum pulses is generated, the pulse generator 20 has to “wait” anamount of time—specified according to the output of the pseudo-randomnumber generator—before generating the subsequent spread spectrum pulse.The varying time periods of the spread-spectrum pulses correspond to aspreading in the frequency spectrum or frequency domain, which is shownin FIG. 14 and discussed below in more detail.

Still referring to FIG. 13, the example spread-spectrum pulses 1001,1002, and 1003 have their respective pulse widths 1021, 1022, and 1023.In some embodiments, the pulse widths 1021, 1022, and 1023 are equal toone another. In other embodiments, the pulse widths 1021, 1022, and 1023may be configured to have different values too. The examplespread-spectrum pulses 1001, 1002, and 1003 have their respectivestimulation amplitudes 1031, 1032, and 1033. In some embodiments, theamplitudes 1031, 1032, and 1033 are equal to one another. In otherembodiments, the amplitudes 1031, 1032, and 1033 may be configured tohave different values too. The spread-spectrum pulses 1001-1003 areconfigured to not cause paresthesia. Paresthesia may refer to a tinglingor a numbing sensation felt by the patient in response to electricalstimulation, and in some cases paresthesia may mask pain, therebyleading to therapeutic relief. In some embodiments, the spread-spectrumpulses 1001-1003 have sufficiently narrow pulse widths 1021-1023, and/orsufficiently low stimulation amplitudes 1031-1033, such that theapplication of the pulses 1001-1003 does not recruit the deep nervefibers that are needed to cause paresthesia. This is also referred to assub-threshold stimulation. In some embodiments, the pulse width of thespread-spectrum pulses 1001-1003 has a range between about 1 microsecondand about 10,000 microseconds.

Still referring to FIG. 13, the stimulation waveform 1000 also includesparesthesia-inducing pulses (also referred to as “tonic pulses”interchangeably hereinafter), two example of which are illustrated aspulses 1050-1051 herein. The paresthesia-inducing pulses 1050-1051 occurperiodically at a fixed frequency that is substantially lower than thefrequency range of the spread-spectrum pulses 1001-1003. For example,the tonic pulses 1050-1051 have a period of 1055, which is fixed betweenany two adjacent tonic pulses for a given stimulation waveform. Ofcourse, the frequency (and the period 1055) of the tonic pulses may beprogrammed (as a programmable stimulation parameter) to change fromwaveform to waveform. But for any given waveform, the tonic pulses havea fixed frequency (and a fixed period 1055 between pulses). Again, thisis in contrast with the spread-spectrum pulses 1001-1003, which havevarying frequencies and periods even within a given stimulationwaveform. The programming of the stimulation waveforms is described inmore detail in U.S. Pat. No. 9,471,753, which was filed on Aug. 31,2012, issued on Oct. 18, 2016, and entitled “Programming And VirtualReality Representation Of Stimulation Parameter Groups,” the disclosureof which is hereby incorporated by reference in its entirety. In someembodiments, a given stimulation waveform corresponds to a stimulationprogram discussed in U.S. Pat. 9,471,753. For example, during theexecution of a certain stimulation program—with its various stimulationparameters (e.g., stimulation amplitude, frequency, pulse width)specified by a programmer—the stimulation program will produce a givenstimulation waveform, which according to the present disclosure mayinclude both the spread-spectrum pulses that have no fixed frequency, aswell as the tonic pulses that have a fixed frequency.

In some embodiments, the frequency of the tonic pulses 1050-1051 is atleast an order of magnitude (e.g., 10 times) lower than the frequencyrange of the spread-spectrum pulses 1001-1003. For example, inembodiments where the frequencies of the spread-spectrum pulses1001-1003 are in the kilo-Hertz (kHz) range, the tonic pulses 1050-1051have a frequency range of between 20 Hz and 700 Hz, for example afrequency of 60 pulses per second (60 Hz). In other embodiments, thetonic pulses 1050-1051 have a frequency that is in the tens of Hz or inthe hundreds of Hz.

The tonic pulses 1050-1051 have pulse widths 1060 and 1061,respectively. The tonic pulses 1050-1051 also have stimulationamplitudes 1070 and 1071, respectively. The pulse widths 1060-1061and/or the stimulation amplitudes 1070-1071 of the tonic pulses1050-1051 are configured so that the tonic pulses 1050-1051 causecomfortable paresthesia in the target patient to whom the stimulationwaveform 1000 is applied as a part of neurostimulation therapy. In orderto produce paresthesia, the tonic pulses 1050-1051 need to deliverenough energy to recruit deeper nerve fibers than what thespread-spectrum pulses 1001-1003 can recruit. As such, the pulse widths1060-1061 and/or the stimulation amplitudes 1070-1071 need to beconfigured to sufficiently large to deliver such energy. Compared to thespread-spectrum pulses 1001-1003, the tonic pulses 1050-1051 may haveeither much greater pulse widths, or much greater stimulationamplitudes, or both. In some embodiments, the pulse width of each of thetonic pulses 1050-1051 is in a range between about 1 microsecond andabout 10,000 microseconds. The pulse width and the frequency of thetonic stimulation will determine an available gap (e.g., time period inwhich the spread-spectrum pulses may occur) for the spread-spectrumstimulation (also referred to as spectral stimulation).

Due to the much lower frequency of the paresthesia-inducing tonicpulses, there may be many spread-spectrum pulses 1001-1003 between twoadjacent tonic pulses 1050-1051. Due the space limitations, FIG. 13illustrates only three of the spread-spectrum pulses 1001-1003 asexamples, but it is understood that there may be several tens (or evenhundreds) of the spread-spectrum pulses between each adjacent pair oftonic pulses. The exact number of the spread-spectrum pulses betweeneach adjacent pair of the tonic pulses may vary as well, due to thepseudo-random nature of the frequency of the spread-spectrum pulses. Inother words, there may be an M number of spread-spectrum pulses betweenone adjacent pair of the tonic pulses, but there may be an N number ofspread-spectrum pulses between another adjacent pair of the tonicpulses.

Another important characteristic of the stimulation waveform 1000 isthat there is a predefined “refractory interval” between the start of aparesthesia-inducing tonic pulse and the end of the recovery phase of apreceding spread-spectrum pulse. For example, FIG. 13 illustrates anexample refractory interval 1080 between the start of the activestimulation phase of the tonic pulse 1051 and the end of the recoveryphase for the preceding spread-spectrum pulse 1003. The refractoryinterval 1080 has to be sufficiently long, so as to allow the neurons(that have been stimulated by the high-frequency spread-spectrum pulsespreceding the tonic pulse) to depolarize so that they can be repolarizedby the tonic pulse 1051.

Referring to FIG. 14, a frequency domain plot of the stimulationwaveform 1000 is illustrated. The time-domain-to-frequency-domaintransformation may be done via a Fourier Transform, for example. TheX-axis represents frequency (e.g., frequency of the pulses of thestimulation waveform), and the Y-axis represents magnitude (e.g.,magnitude of the pulses of the stimulation waveform, which may be indecibels, or in a logarithmic scale). In some embodiments, FIG. 14illustrates the amount of energy occupying each frequency band.

As FIG. 14 clearly shows, the paresthesia-inducing component (i.e., thetonic pulses 1050-1051 shown in FIG. 13) of the stimulation waveform1000 manifests itself as a very “narrow” pulse (with a center frequency)in the frequency domain, whereas the spread-spectrum component of thestimulation waveform 1000 occupies a much “wider” frequency range(hence, the name “spread-spectrum”). The paresthesia-inducing componenthas a much lower center frequency of f1 Hz, and the spread-spectrumcomponent has a much higher frequency range, which is between f2 kHz andf3 kHz. For example, f1 may be 60 , f2 may be 6, and f3 may be 8. Inother words, the frequency of the spread-spectrum pulses may be severalorders of magnitude higher than the frequency of theparesthesia-inducing tonic pulses.

In some embodiments, the spread spectrum pulses are configured such thatthe frequencies of the spread spectrum pulses are continuously changingand do not repeat. For example, although a plurality of spread spectrumpulses exist between two adjacent tonic pulses, none of these spreadspectrum pulses will have the same frequency, which means that the timeperiod between any two of the spread spectrum pulses is never equal toanother time period between any of the two other spread spectrum pulses.A simplified example of this embodiment is shown in FIG. 15, whichillustrates a histogram of a number of occurrences for different timeperiods of the spread spectrum pulses. The X-axis represents the timeperiod, for example a time period (e.g., similar to the periods 1010 or1011 of FIG. 13) between any two adjacent spread spectrum pulses. TheY-axis represents the number of occurrences associated with each uniquetime period.

As shown in FIG. 15, a histogram of time periods P1 -P10 is illustrated.In one example, P1 represents a time period between a first spreadspectrum pulse (e.g., 1001 of FIG. 13) and a second spread spectrumpulse (e.g., 1002 of FIG. 13), P2 represents a time period between thesecond spread spectrum pulse and a third spread spectrum pulse, P3represents a time period between the third spread spectrum pulse and afourth spread spectrum pulse, P4 represents a time period between thefourth spread spectrum pulse and a fifth spread spectrum pulse, so onand so forth, such that P10 represents a time period between the tenthspread spectrum pulse and an eleventh spread spectrum pulse (e.g., 1003of FIG. 13). In some embodiments, the first spread spectrum pulse islocated adjacent to the second spread spectrum pulse, the second spreadspectrum pulse is located adjacent to the third spread spectrum pulse,the third spread spectrum pulse is located adjacent to the fourth spreadspectrum pulse, so on and so forth, such that the tenth spread spectrumpulse is located adjacent to the eleventh spread spectrum pulse. As thehistogram in FIG. 15 indicates, each of the time periods P1-P10 only hasa single occurrence, meaning that no time periods are repeated (or notwo time periods of the spread spectrum pulses are the same). For thesake of providing a non-limiting numerical example, P1 may be 0.2 ms, P2may be 0.19 ms, P3 may be 0.22 ms, P4 may be 0.23 ms, P5 may be 0.18 ms,P6 may be 0.185 ms, P7 may be 0.177 ms, P8 may be 0.21 ms, P9 may be0.16 ms, and P10 may be 0.195 ms. Again, none of the two periods are thesame, which means no period occurs more than once.

In some embodiments, not only are the periods between adjacent spreadspectrum pulses non-repeating, but the same is true for periods betweennon-adjacent spread spectrum pulses as well. For example, referring toFIG. 16, an expanded histogram is illustrated. The expanded histogramillustrates time periods P11-P13, as an example subset of the timeperiods between non-adjacent pulses. For example, P11 may represent thetime period between the first pulse and the third pulse, P12 mayrepresent the time period between the first pulse and the fifth pulse,and P13 may represent the time period between the third pulse and theninth pulse. Again, it can be seen that P11 is different from P1-P10 andP12-P13, P12 is different from P1-P11, and P13, and P13 is differentfrom P1-P12, and they each have an occurrence of 1. Since there are manymore permutations of different pulses between which a period time can bedefined, it is understood that FIG. 16 merely shows an incomplete subsetof all the possible time periods corresponding to the different possiblepermutations, for reasons of simplicity. Nevertheless, in the embodimentrepresented by FIG. 16, none of the possible time periods will have anoccurrence more than 1, meaning that there is no repeating time patternassociated with the spread spectrum pulses, which are completelyrandomized.

In the embodiments corresponding to FIGS. 15-16, the time periods P1-13are associated with spread spectrum pulses between two adjacent tonicpulses (e.g., between the tonic pulses 1050-1051 of FIG. 13). In otherwords, within a given time period (e.g., the period 1055 of FIG. 13) ofthe tonic pulses, the time periods of spread spectrum pulses therein arerandomized and non-repeating. In other embodiments, this implementationmay extend to multiple time periods of the tonic pulses as well. Forexample, between a first tonic pulse and a fifth tonic pulse—which spansa time period of four tonic pulse periods—none of the time periodsbetween the spread spectrum pulses has more than a single occurrence.Such a randomized implementation of the spread spectrum pulses may helpprevent habituation, which is a benefit of the present disclosuredisclosed below.

FIG. 17 illustrates a more realistic example of the stimulation waveformhaving a low frequency tonic component and a high frequency spreadspectrum component. For example, a stimulation waveform 1000A isillustrated as a non-limiting example embodiment of the stimulationwaveform 1000 discussed above. The stimulation waveform 1000A is shownin a time domain, for example as a captured waveform from anoscilloscope. As shown in FIG. 17, the stimulation waveform 1000Aincludes a tonic pulse followed by a plurality of spread-spectrumpulses. The tonic pulse may be similar to the pulse 1050 of FIG. 13, andthe spread-spectrum pulses may be similar to the pulses 1001-1003 ofFIG. 13. For example, the tonic pulse has a substantially lowerfrequency than the spread-spectrum pulses, but it has a greateramplitude and a longer pulse width than each of the spread-spectrumpulses. In addition, as discussed above with reference to FIG. 13,though the tonic pulse has a fixed frequency, the spread-spectrum pulseshave no fixed frequency (for a given duration of time), which isevidenced in FIG. 17 by the fact that the time intervals separating thespread-spectrum pulses are constantly changing and do not remain fixed.

One difference between the stimulation waveforms 1000 and 1000A is that,unlike the pulses in FIG. 13—which have active recoveries—the tonicpulse of the stimulation waveform 1000A has a passive recovery portionfollowing an active stimulation portion, and that the spread-spectrumpulses collectively have a passive recovery portion following aplurality of active stimulation pulses. In other embodiments, activerecoveries may be implemented for the tonic pulse and/or thespread-spectrum pulses in a manner similar to the stimulation waveform1000 discussed above with reference to FIG. 13. In addition, a passiverecovery may be implemented for each spread-spectrum pulse, rather thana single recovery for a plurality of spread-spectrum pulse, as shown inFIG. 17.

FIG. 18 is a simplified example stimulation waveform without thespread-spectrum stimulation component (also referred to as spectralstimulation) in a time domain according to various aspects of thepresent disclosure. The omission of the spread-spectrum component doesnot mean that the spread-spectrum component is missing in the actualwaveform, but that it is just not shown in FIG. 18 for reasons ofsimplicity. In other words, among other things, FIG. 18 illustrates aspectral stimulation block in a time domain that is reserved for thespectral stimulation pulses, but the individual spectral stimulationpulses are not specifically illustrated in FIG. 18 for reasons ofsimplicity. In more detail, FIG. 18 illustrates the spectral stimulationblock as a “gap”—an available time period in which the spread-spectrumpulses can occur. The “gap” is denoted as t_(spectrum), and it can becalculated as a function of the following: a period of the tonic pulses(denoted as t_(tonic)), a pulse width of each tonic pulse (denoted asPW_(tonic) a time length of the recovery phase of the tonic pulse(denoted as t_(recov) _(_) _(tonic)), and a time length of the recoveryphase of the spread-spectrum stimulation pulses (denoted as y_(recov)_(_) _(spec)). In some embodiments,t_(spectrum)=t_(tonic)−PW_(tonic)−t_(recov tonic)−t_(recov spec). Also,it is understood that even though FIG. 18 illustrates the recoveryphases for the tonic stimulation and the spectral stimulation as beingpassive recovery phases, they may be active recovery phases in otherembodiments, and the formula for calculating t_(spectrum) remains thesame.

It is understood that the spread spectrum pulses discussed above aredifferent from burst pulses (also referred to as burst stimulation).Examples of burst pulses are described in U.S. Pat. No. 8,364,273entitled “Combination of Tonic and Burst Stimulations to TreatNeurological Disorders”. In burst stimulation, the waveform may includetonic pulses and burst pulses that have different frequencies from thetonic pulses. However, the burst pulses still have a fixed frequency,even if that fixed frequency is different from the fixed frequency ofthe tonic pulses. As such, the burst pulses have fixed periods in thetime domain for any given waveform. In contrast, the spread spectrumpulses discussed above have no fixed frequency for a given duration oftime (demonstrated by the lack of a single “peak” of the spread spectrumpulses in FIG. 14), and they do not have fixed periods (demonstrated bythe uneven/unequal time periods 1010 and 1011 in FIG. 14, which is alsoshown as “jitter”).

It is also understood that although the embodiments discussed above havedemonstrated a stimulation waveform with a fixed frequency toniccomponent, the fixed frequency is not required for the tonic componenteither. For example, in some alternative embodiments, the tonic pulsesmay have multiple frequencies, for example the tonic pulses may have afirst frequency of 60 Hz for a first period of time (e.g., 10 minutes),and then change into a second frequency of 50 Hz for a second period oftime (e.g., another 10 minutes after the first 10 minutes). In such anembodiment, the tonic pulse component still has a fixed frequency forany given period of time while the spread-spectrum pulses continuallyshift in frequency, but that the tonic pulse component may still shiftin frequency (e.g., for one low frequency to another low frequency) fromtime to time. In further embodiments, it is understood that the tonicpulse component may also have a spread-spectrum-like behavior. Forexample, even within a given period of time, the tonic pulse component(or rather, the low frequency component, since it no longer has a fixedfrequency) may have varying frequencies, which may manifest in the timedomain as not having fixed periods between adjacent pulses.

One benefit offered by the stimulation waveform discussed above (e.g.,the stimulation waveform 1000) is that it prevents habituation.Habituation may refer to the neurons getting accustomed to the samestimulation frequency, and as such the neurons become less responsive tobeing stimulated by that same stimulation frequency. Consequently, thisdegrades the efficacy of the stimulation therapy. Another example ofhabituation may refer to an audio noise generated by the pulsegenerator, which can be detected by some patients as a high pitchedbuzz. This audio noise may become annoying to these patients. Incomparison to most conventional neuro-stimulation systems that onlygenerate pulses with a fixed frequency, the pulse generator of thepresent disclosure generates a stimulation waveform 1000 that includesthe spread-spectrum component, which as discussed above does not have afixed stimulation frequency. Thus, the stimulation waveform 1000 caneffectively prevent or at least reduce the undesirable habituation.

As another benefit, the stimulation waveform 1000 offers better efficacyfor patients compared to conventional stimulation waveforms. This isattributed to the fact that the stimulation waveform 1000 includes boththe low frequency tonic component and the high frequency spread spectrumcomponent. The tonic component can induce paresthesia, whose coveragearea can be configured (e.g., by adjusting the stimulation parametersassociated with the tonic stimulation) to mask pain. The spread spectrumcomponent, which may be configured to be subthreshold (e.g., below aperception threshold or a paresthesia threshold), may provide additionaltherapeutic relief where paresthesia may be inadequate.

The foregoing has outlined features of several embodiments so that thoseskilled in the art may better understand the detailed description thatfollows. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A pulse generator, comprising: charging circuitryconfigured to provide electrical power to the pulse generator;communication circuitry configured to conduct wirelesstelecommunications with external programming devices, thetelecommunications containing programming instructions sent from theexternal programming devices; and stimulation circuitry configured togenerate electrical pulses based on the programming instructions,wherein the electrical pulses include a first component that isparesthesia-inducing and a second component that isnon-paresthesia-inducing.
 2. The pulse generator of claim 1, wherein:the first component has a fixed frequency; and the second component hasa spread-spectrum frequency range, wherein a lower limit of thespread-spectrum frequency range is greater than the fixed frequency. 3.The pulse generator of claim 1, wherein an amplitude of the firstcomponent is greater than an amplitude of the second component.
 4. Thepulse generator of claim 3, wherein the spread-spectrum frequency rangeis at least an order of magnitude greater than the fixed frequency. 5.The pulse generator of claim 2, wherein the second component includes aplurality of pulses that occur at non-fixed time intervals.
 6. The pulsegenerator of claim 5, wherein the pulse generator includes apseudo-random number generator, and wherein the non-fixed time intervalsoccur based on an output of the random number generator.
 7. The pulsegenerator of claim 5, wherein none of the non-fixed time intervals has avalue that is equal to any of the other non-fixed time intervals.8. Thepulse generator of claim 1, wherein in a time domain: the firstcomponent includes a plurality of tonic pulses; the second componentincludes a plurality of sub-tonic pulses; and a plurality of thesub-tonic pulses occur between each pair of the tonic pulses.
 9. Thepulse generator of claim 8, wherein an amount of time that occur elapsesbetween each pair of the tonic pulses is a pseudo-random number.
 10. Thepulse generator of claim 8, wherein a refractory interval exists betweeneach tonic pulse and an immediately-preceding sub-tonic pulse, andwherein the refractory interval is configured to be sufficiently long toallow for nerve fibers stimulated by the sub-tonic pulses to repolarize.11. The pulse generator of claim 1, wherein a pulse width of the firstcomponent is greater than a pulse width of the second component.
 12. Amethod, comprising: receiving, via communication circuitry on a pulsegenerator, programming instructions from a programming device that isexternal to the pulse generator; and generating electrical pulses viastimulation circuitry on the pulse generator, wherein stimulationparameters of the electrical pulses are based on the receivedprogramming instructions, and wherein the electrical pulses include afirst component that is paresthesia-inducing and a second component thatis non-paresthesia-inducing.
 13. The method of claim 12, wherein: thefirst component has a fixed frequency; and the second component has aspread-spectrum frequency range, wherein a lower limit of thespread-spectrum frequency range is greater than the fixed frequency. 14.The method of claim 12, wherein: an amplitude of the first component isgreater than an amplitude of the second component; a pulse width of thefirst component is greater than a pulse width of the second component;the spread-spectrum frequency range is at least an order of magnitudegreater than the fixed frequency; and the second component includes aplurality of pulses that occur at non-fixed time intervals based on anoutput of the random number generator.
 15. The method of claim 14,wherein none of the non-fixed time intervals has a value that is equalto any of the other non-fixed time intervals.
 16. The method of claim12, wherein in a time domain: the first component includes a pluralityof tonic pulses; the second component includes a plurality of sub-tonicpulses; and a plurality of the sub-tonic pulses occur between each pairof the tonic pulses.
 17. The method of claim 12, wherein: an amount oftime that occur elapses between each pair of the tonic pulses is apseudo-random number; and a refractory interval exists between eachtonic pulse and an immediately-preceding sub-tonic pulse, and whereinthe refractory interval is configured to be sufficiently long to allowfor nerve fibers stimulated by the sub-tonic pulses to repolarize.
 18. Amedical system, comprising: an electronic programming device configuredto generate programming instructions in response to user input; and apulse generator configured to generate electrical pulses based on theprogramming instructions, wherein the electrical pulses include a firstcomponent that is paresthesia-inducing and a second component that isnon-paresthesia-inducing; wherein: the first component has a fixedfrequency; and the second component has a spread-spectrum frequencyrange, wherein a lower limit of the spread-spectrum frequency range isgreater than the fixed frequency.
 19. The medical system of claim 18,wherein: an amplitude of the first component is greater than anamplitude of the second component; a pulse width of the first componentis greater than a pulse width of the second component; thespread-spectrum frequency range is at least an order of magnitudegreater than the fixed frequency; and the second component includes aplurality of pulses that occur at non-fixed time intervals based on anoutput of the random number generator.
 20. The medical system of claim12, wherein in a time domain: the first component includes a pluralityof tonic pulses; the second component includes a plurality of sub-tonicpulses; and a plurality of the sub-tonic pulses occur between each pairof the tonic pulses; wherein: an amount of time that occur elapsesbetween each pair of the tonic pulses is a pseudo-random number; and arefractory interval exists between each tonic pulse and animmediately-preceding sub-tonic pulse, and wherein the refractoryinterval is configured to be sufficiently long to allow for nerve fibersstimulated by the sub-tonic pulses to repolarize.